Commands using cat (514)

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GREP a PDF file.
PDF files are simultaneously wonderful and heinous. They are wonderful in being ubiquitous and mostly being cross platform. They are heinous in being very difficult to work with from the command line, search, grep, use only the text inside the PDF, or use outside of proprietary products. xpdf is a wonderful set of PDF tools. It is on many linux distros and can be installed on OS X. While primarily an open PDF viewer for X, xpdf has the tool "pdftotext" that can extract formated or unformatted text from inside a PDF that has text. This text stream can then be further processed by grep or other tool. The '-' after the file name directs output to stdout rather than to a text file the same name as the PDF. Make sure you use version 3.02 of pdftotext or later; earlier versions clipped lines. The lines extracted from a PDF without the "-layout" option are very long. More paragraphs. Use just to test that a pattern exists in the file. With "-layout" the output resembles the lines, but it is not perfect. xpdf is available open source at http://www.foolabs.com/xpdf/

Generat a Random MAC address
Just increase the 1 at the end if you want to generate more than one. (Alternative to "| head -n N" you could use the -b flag of od: -b $[6*N]

Bitcoin Brainwallet Exponent Calculator
A bitcoin "brainwallet" is a secret passphrase you carry in your brain. The Bitcoin Brainwallet Exponent Calculator is one of three functions needed to calculate the bitcoin PRIVATE key. Roughly, the formula is exponent = sha256 (passphrase) Note that this is a bash function, which means you have to type its name to invoke it. You can check the accuracy of the results here http://brainwallet.org

Display top 5 processes consuming CPU

Advanced python tracing
Trace python statement execution and syscalls invoked during that simultaneously

Convert CSV to JSON
Replace 'csv_file.csv' with your filename.

Verbosely delete files matching specific name pattern, older than 15 days.

Download SSL server certificate with opsnessl
Useful when we need to create new certificate for site when current one is near expiry. This downloaded cert can be used to provide organisational data directly to new cert. using below command. e.g. openssl x509 -x509toreq -in /tmp/example.com.cert -out example.com.csr -signkey example.com-key.pem

Set an alarm to wake up [2]
Set an alarm to starts in specific time.

Get your external IP address ( 10 characters long )
Shortest url to a external IP-service, 10 characters.


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